The present invention relates to a crankcase or cylinder block for an internal combustion engine of any type, for example the V-shaped block or the in-line cylinder type block.
During operation of an internal combustion engine, combustion gas leaks occur at the piston rings causing the presence of unused gas in the crankcase. These crankcase gases must be exhausted to prevent a pressure rise in the crankcase that can reduce engine power as well as cause other undesirable effects. It is further desirable to recycle into the crankcase any engine oil introduced into the cylinder head, for example, from lubrication of the valves.
Crankcases have been proposed wherein internal conduits are provided to connect the crankcase surface facing the cylinder head with lower compartments separating the crankshaft bearings, in order to exhaust crankcase gases and recycle the engine oil.
However, these internal conduits of the prior art are complex in their configuration and have small cross sections for the passage of gas and oil. Furthermore, the conduits are obtained by machining or by means of core pins or fragile mold cores, so that the crankcases manufactured in this manner are expensive and lack adequate rigidity.